MgCl2乳化液的制备及其在豆腐生产中的应用

Study on MgCl_2 emulsion and its application in tofu

【目的】针对豆腐凝固剂MgCl2在点豆浆过程中反应过快的缺点,制备油包水型MgCl2乳化液,以降低MgCl2在豆浆中的分散速度,提高豆腐的细腻度。【方法】用MgCl2.6 H2O制备油包水型MgCl2乳化液,研究不同乳化剂(卵磷脂、分子蒸馏单甘酯、蔗糖脂肪酸酯、山梨糖醇酐硬脂酸酯、单月桂酸甘油酯)及其用量(质量分数0.5%,1.0%,1.5%,2.0%,2.5%,3.0%)、水相(MgCl2、蒸馏水)/油相(卵磷脂、大豆油)的比例(质量比40/60,50/50,55/45,60/40,65/35,70/30,80/20)、MgCl2.6 H2O用量(质量分数15%,20%,25%,30%)及乳化工艺(乳化温度(20,30,40,50,60,70℃)、转速(3 000,4 000,5 000,6 000,7 000 r/min)、时间(1,2,5,7,10,15 min))对MgCl2乳化液稳定性和黏度的影响,并对用MgCl2乳化液作为凝固剂制得的豆腐与其他种类豆腐进行品质比较。【结果】MgCl2乳化液的配方和乳化工艺:水相(MgCl2.6 H2O用量为质量分数30%,蒸馏水30%)/油相(卵磷脂用量为质量分数1.5%,大豆油质量分数38.5%)为60/40,按上述配方分别配制水相和油相,水浴加热到50℃,将水相缓慢加入油相中,用高剪切混合乳化机以5 000 r/min乳化10 min,最后进行杀菌和灌装,即可得到均匀稳定的MgCl2乳化液。以制备的MgCl2乳化液作为凝固剂可以降低豆浆的凝固速率,制得的豆腐与其他种类豆腐相比,光滑细腻度更好,风味更佳。【结论】制备获得了稳定的油包水型MgCl2乳化液,其可降低豆腐的凝固反应速率,制得风味鲜美、光滑细腻的新型豆腐。

[Objective] In view of coagulant＇s high solubility, the objective of this study was to reduce the reaction rate of MgC12 in soymilk. [Method] This paper studied the effect of optimum dosage（0.5%, 1.0%,1. 5%,2. 0%,2. 5%,3.0%） of W/O emulsifiers（lecithin,monoglyceride,sucrose ester, span 60, glycerol monolaurate）, concentration of MgCl2·6H2O（15 %, 20 %, 25 %, 30 % ）, the ratio of water/oil （40/ 60,50/50,55/45,60/40,65/35,70/30,80/20）, the optimum emulsifying temperature （20,30,40,50,60,70℃）,stirring speed（3 000,4 000,5 000,6 000,7 000 r/min） and stirring time（1,2,5,7,10,15 min） on the stability and viscosity of emulsion. The emulsion was used as a coagulant for tofu and compared it with other types of tofu. [Result] The optimum conditions were as follows：the ratio of water/oil was 60/40,30% MgCl2·6H2O, 1.5 % lecithin, emulsifying temperature 50 ℃, stirring speed 5 000 r/min,and stirring time 10 min. The emulsion can reduce reaction rate of soymilk,and produce delicious and smooth tofu. [Conclusion] Emulsifying MgCl2 can reduce reaction rate as new tofu coagulant,and produce delicious and smooth tofu.